Another example of personification may be seen in the recumbent figures of river-gods--notably that of the Nile, with his sixteen cubits, as babies, playing around him. River-gods were indeed an object of worship from early times in Greece, and so appear on coins and elsewhere; but this figure of the Nile, a product of Alexandrian art, is not like the earlier gods, who were looked upon as the givers of increase and fertility; it is a mere allegorical impersonation of the river, such as might be made by a modern artist who made no pretence to believe in the existence of such an anthropomorphic river-god. It cannot be counted as religious art at all. And the attributes and accessories of such a figure, the crocodile and hippopotamus, the sphinx and corn and horn of plenty, are all of them symbolic allusions such as are suitable to such a frigid personification. The art of Alexandria is full of such devices; that of Pergamon is more vigorous and dramatic; but in both alike we find the influence of a learned study of mythology, full of quaint and far-fetched allusions and symbols. The culmination of this learned mythology is to be seen in the great altar of Pergamon, on which the gods who are in combat with the giants include not only all figures, appropriate and inappropriate, from the Hellenic pantheon, but many other deities whose right of admission to that pantheon is more than doubtful. The figures of the gods no longer correspond to the belief in any real divinities, but are either mere artistic types, repeated again and again in accordance with convention, or else they are regarded as symbols representing different aspects of divine power.